<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
   <div></div>
   <script>
    console.log(location.search);//?uname=andy
    //1.先去掉？ substr('起始的位置'，截取几个字符)；
    var params = location.search.substr(1);//uname = andy
    console.log(params);
    // 2. 利用=把字符串分割为数组 split('=');
    var arr = params.split('=');
    
    console.log(arr); // ["uname", "ANDY"]
    var div = document.querySelector('div');
    // 3.把数据写入div中
    div.innerHTML = arr[1] + '欢迎您';
   </script> 
</body>
</html>